Summary:
The lysyl-tRNA synthetase LysS is a member of the family of aminoacyl tRNA synthetases, which interpret the genetic code by covalently linking amino acids to their specific tRNA molecules. The reaction is driven by ATP hydrolysis. LysS belongs to the subclass IIb of aminoacyl tRNA synthetases. E. coli contains both a constitutive and an inducible lysyl tRNA synthetase; lysS encodes the constitutively expressed enzyme.

Key residues for recognition of the cognate amino acid and catalytic activity have been identified [Ataide04], providing insight into differences between the class I and class II tRNA synthetases. A model for the recognition specificity of the cognate anticodon is presented [Commans98].

Under aerobic conditions and at growth temperatures below 37 degrees C, LysS is required for normal growth [Leveque91]; the growth defect can be suppressed by overexpression of lysU, the gene encoding the inducible lysyl tRNA synthetase [Kawakami92].

Solution structures [Commans95] and a crystal structure [Onesti00] of LysS are presented, revealing reorganization of the active site upon lysine binding.